I live by the Lake of the Ozarks and we almost never see a mosquito here. Of course I don't spend a lot of time outside after dark but it amazes me how few there are. Even when golfing in the late afternoon, and we have three ponds on the course.
However, the bottom dropped out of our temperature on Sept 1st. It went from the upper 90's to the lower 60's in two days.
The Army Sniper School has trained some counter-snipers to deal with them.
Seriously, that's not the first time I've heard of mosquitoes killing livestock or even people. Folks around Stuttgart AR talk about folks being stripped nekkid and dumped out in the rice paddies for the mosquitoes to deal with them.
Mosquitoes are always real bad around hear after hurricanes that bring lots of rain. When areas flood that have not flooded for a long time those mosquito eggs that were laying there dormant for all those years. As soon as they get wait they start the process to hatch.